Publication Abstracts
Li et al. 2020
Li, J., R.A. Kahn, J. Wei, , , Z. Li, X. Li, O. Dubovik, and T. Nakajima, 2020: Synergy of satellite- and ground-based aerosol optical depth measurements using an ensemble Kalman filter approach. J. Geophys. Res. Atmos., 125, no. 3, e2019JD031884, doi:10.1029/2019JD031884.
Satellite and ground-based remote sensing are two widely-used techniques to measure aerosol properties. However, neither is perfect, in that satellite retrievals suffer from various sources of uncertainties, and ground observations have limited spatial coverage. In this study, focusing on improving estimates of aerosol information on large scale, we develop a data synergy technique based on the Ensemble Kalman Filter (EnKF) to effectively combine these two types of measurements and yield a monthly mean aerosol optical depth (AOD) product with global coverage and improved accuracy. We first construct a 474-member ensemble using 11 monthly mean AOD datasets to represent the variability of the AOD field. Then Moderate Resolution Imaging Spectroradiometer (MODIS) AOD retrievals are selected as the background field into which ground-based measurements from 135 Aerosol Robotic Network (AERONET) sites are assimilated using the EnKF. Compared with satellite data, the bias and root-mean-square errors (RMSE) of the combined field are greatly reduced and correlation coefficients are greatly improved. Moreover, cross-validation shows that at locations where surface observations were not assimilated, the reduction in RMSE and bias and the increase in correlation can still reach ∼20%. Locations where the spatial representativeness of AOD is large or the site density is high are where the greatest changes are typically found. This study shows that the EnKF technique effectively extends the information obtained at surface sites to a larger area, paving the way for combining information from different types of measurements to yield better estimates of aerosol properties as well as their space-time variability.
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BibTeX Citation
@article{li06110m,
author={Li, J. and Kahn, R. A. and Wei, J. and Carlson, B. E. and Lacis, A. A. and Li, Z. and Li, X. and Dubovik, O. and Nakajima, T.},
title={Synergy of satellite- and ground-based aerosol optical depth measurements using an ensemble Kalman filter approach},
year={2020},
journal={J. Geophys. Res. Atmos.},
volume={125},
number={3},
pages={e2019JD031884},
doi={10.1029/2019JD031884},
}
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RIS Citation
TY - JOUR ID - li06110m AU - Li, J. AU - Kahn, R. A. AU - Wei, J. AU - Carlson, B. E. AU - Lacis, A. A. AU - Li, Z. AU - Li, X. AU - Dubovik, O. AU - Nakajima, T. PY - 2020 TI - Synergy of satellite- and ground-based aerosol optical depth measurements using an ensemble Kalman filter approach JA - J. Geophys. Res. Atmos. VL - 125 IS - 3 SP - e2019JD031884 DO - 10.1029/2019JD031884 ER -
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